JP2003056307A - Turbo machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To compensate axial thrust with respect to a turbo expander which is automatically adjustable and automatically meets an operation condition of various turbo expanders. SOLUTION: This turbo machine comprises: a measuring device 7 for directly detecting a thrust force of a rotor shaft 2 supported inside a rolling bearing 8; and at least two pressure control valves controlled by a controller 9 in a control conduit. A rotor piston surface 14 in any one back surface of a rotor disc 5 and 3, closed with respect to a case 1 via the control conduit, is capable of operating pressure which performs control in inlet and outlet of a stage, and the controller 9 operates the pressure control valves depending on the measured thrust force in order to eliminate the thrust force arranged outside a predetermine allowance range by pressure increase or pressure decrease in the rotor piston surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a case, a rotor shaft, and a rotor disk of an expansion turbine stage which is movably disposed at one shaft end portion of the rotor shaft and which is made to flow through the centripetal axis. , A rotor machine movably arranged at the other shaft end of the rotor shaft, the rotor disk of a compressor stage being flowed through in the radial direction.

[0002]

BACKGROUND OF THE INVENTION Turbomachines of the above construction, called turboexpanders, are operated at high pressure levels in industrial use, where often the axially oriented turbine outlet pressure of the rotor shaft is similar. Significant deviations from the axially aligned compressor inlet pressure. Due to this pressure difference between the compressor stage and the expansion turbine stage, a large axial thrust is exerted on the rotor shaft operating at high rpm. Indeed, this axial transition force is fully accommodated by a well-sized thrust bearing, but manufactured thrust bearings designed to accommodate high operating-axis thrust and shock have significant loss efficiency. Also accommodate. The loss efficiency of the thrust bearing set for the case of unfavorable operation amounts to 5-10% of the turbine expansion efficiency. Correspondingly, the drive efficiency available in the compressor stage is reduced, which reduces the overall efficiency of the installation, for example the refrigeration installation in which the turbomachine is used.

It would also be advantageous to use a high precision angular contact ball bearing which produces only a small loss at very high speeds. These angular contact ball bearings have a special construction of 2.5 × 10 ⁶ mm / m 2.
It is possible to operate with a rotational speed-diameter-product up to in. This value is sufficient, for example, to operate a refrigeration turboexpander with an expansion pressure ratio p _Ein / p _Aus = 10 in the expansion turbine stage. High precision rolling bearings generally achieve an acceptable life only when the rolling bearing is exposed to small forces, especially small axial forces, in continuous operation. Acceptable values are not sufficient to accommodate the axial thrust and shocks that occur when operating a turbo expander when making adjustments.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a turboexpander with automatic thrust adjustment, and to automatically perform axial thrust compensation suitable for operating conditions of various turboexpanders. To do.

[0005]

The object of the present invention and the solution to this problem are to provide a case, a rotor shaft, and a centripetal flow through which is movably arranged at one end of the rotor shaft. A rotor disk of an expansion turbine stage, a rotor disk of a compressor stage movably disposed at the other shaft end of the rotor shaft, and a rotor disk of a compressor stage rotatably supported in a rolling bearing. A measuring device for directly detecting the axial thrust of the shaft and at least two pressure regulating valves controlled by regulators in the control conduit, wherein the control conduit seals against the case The rotor piston surface on the one rear side of the rotor disk is capable of exerting a predominant pressure at the inlet and outlet of the stage, and the regulator is A pressure regulating valve in the control conduit which is acted on by a high pressure, depending on the measured axial thrust, in order to eliminate the axial thrust located outside the constant tolerance region by increasing or decreasing the pressure on the rotor piston face. Or a turbomachine configured to operate either a pressure regulating valve in a control conduit that is under low pressure.

For example, the rotor piston surface may be provided on the back surface of the compressor rotor disk. Via the control conduit, the rotor piston face is arranged to be able to act on the pressure prevailing at the inlet to the compressor stage and at the outlet of the compressor stage,
The regulator may be a pressure regulating valve in the control conduit which is acted upon by the compressor inlet pressure, depending on the measured axial thrust.
It is configured to operate any of the pressure regulating valves in the control conduit that are under compressor outlet pressure. However, a configuration according to claim 3 is also present within the framework of the invention, in which the rotor piston face is provided on the rear face of the rotor disk of the expansion turbine stage.

Due to the rolling bearing portion of the rotor shaft, an acceptable shaft thrust is fixed. During operation of the turbomachine, a regulator compares the axial thrust measurements contained by the measuring device with a predetermined reference range. If the measured axial thrust lies outside the reference range, then one of the two pressure regulating valves is controlled for the purpose of calibrating the axial thrust.
The pressure regulating valve allows the pressure at the rotor piston face to be sensitively regulated. The pressure at the rotor piston face is either increased or decreased depending on which direction the axial thrust has to be modified.

In another configuration, the invention provides that the additional control conduits each comprise a valve, the rear surface of the other rotor disc being sealed to the case via the additional control conduits. Another rotor piston surface at
It is taught that the pressure prevailing at the inlet of this stage and the pressure at the outlet of this stage are operable.

The valve of the additional control conduit can be designed as a pressure regulating valve, which is likewise controlled by the regulator.
The control of the pressure regulating valves in the control conduit and the additional control conduit then complements the pressure variations at the rotor piston faces of the compressor rotor disc and the turbine rotor disc so that the compensating force for axial thrust compensation is increased. Is done as follows. In that respect, the pressure regulating valve is switched, for example, such that an increase in pressure at the rotor piston face of the compressor stage is combined with a pressure decrease at the rotor piston face of the turbine rotor disk. Correspondingly, the pressure reduction at the rotor piston face of the compressor rotor disc is combined with the pressure increase at the rotor piston face of the turbine rotor disc. In the case of the arrangement according to the invention, a very large compensation force can be obtained and adjusted precisely, so that the axial thrust of the rotor shaft is in a narrow reference value range which is acceptable for high-precision rolling bearings. Stay inside.

It is also within the framework of the invention that the valve of the additional control conduit is designed to be a switching valve which opens rapidly, for example a magnetic valve. The use of a quick-open switching valve is provided to quickly correct impact-style axial thrust changes. The additional rotor piston faces are then rapidly actuated with sufficient low pressure or high pressure, respectively.

The measuring device has the excellent structure of the present invention.
A ring-shaped force accommodating portion is provided, and the force accommodating portion is arranged between the outer ring of the case-side rolling bearing that receives a load by the axial thrust of the rotor shaft and the corresponding contact surface of the case. The force receiver can be equipped with a wire strain gauge and thus, in a time-independent manner, without constant axial thrust, such as in the almost static axial bearing pretensioning without the pressure effect of a turbomachine. I'm done.

[0012]

The invention will now be described with reference to the drawings, which show only one embodiment.

In the basic structure of the turbomachine shown in each drawing, a case 1, a rotor having a rotor shaft 2 supported by a rolling bearing, and a rotor shaft 2 having a rotor shaft 2 movable at one shaft end portion thereof. And a rotor disk 3 of an expansion turbine stage 4 that is centripetically passed therethrough, and a radially passed compression that is movably disposed at the other shaft end of the rotor shaft 2. And a rotor disk 5 of a machine stage 6. The turbomachine is equipped with a measuring device 7 for directly detecting the axial thrust of the rotor shaft 2 supported in a rolling bearing 8 and equipped with at least two pressure regulating valves 10, 11 controlled by a regulator 9. Prepare One pressure regulating valve 10 is arranged in a control conduit 12 connected to the inlet of the compressor stage 6. The other pressure control valve 11
Are arranged in a control conduit 13 which is connected to the outlet side of the compressor stage 6.

The rotor piston surface 14 at the back of the compressor rotor disk 5, which is sealed to the case 1 via the control conduits 12 and 13, has a low pressure p ₁ which prevails at the inlet to the compressor stage, It is possible to work with a high pressure p _{2 at} the outlet of the compressor stage 6. The regulator 9 eliminates axial thrusts located outside of the predetermined tolerance range by increasing or decreasing the pressure on the rotor piston face 14, depending on the measured axial thrust, the compressor inlet pressure p ₁ Operated either by the pressure regulating valve 10 in the control conduit 12 or by the pressure regulating valve 11 in the control conduit 13 which is below the compressor outlet pressure p ₂ . From each figure it can be seen that the control conduits 12, 13 at the back of the compressor rotor disk 5 are connected to the compressor stage 6 and that the rotor piston surface 14
However, it can be seen that in this embodiment it is formed by the back surface of the compressor rotor disk 6 which is hermetically sealed to the case 1.

The measuring device 7 has a ring-shaped force accommodating portion.
Well, this force storage part is loaded by the axial thrust of the rotor shaft 2.
The outer ring of the rolling bearing 8 on the case side that receives the
It is arranged between the contact surface and the wire strain gauge.
It works with Ji. Force detected by measuring device 7
When the measured value F is located outside the predetermined reference value area ΔF
In this case, one of both pressure regulating valves 10 and 11 is controlled.
It For example, the measured value F is ΔF_sollThe place below
In case of compressor pressure p₁Pressure regulation affected by
The regulating valve 10 is controlled so that the pressure on the rotor piston surface 14 is controlled.
Force until the measured value is again within the predetermined reference range
It can be reduced sufficiently. Measured value F is ΔF_{so ll}On top of the
If rising, first the pressure regulating valve 10 is closed again.
Reverse control is performed until The measured value F is still ΔF_sollof
Only when it is located above the outlet pressure p_TwoAct by
Another pressure regulating valve 1 arranged in the control conduit for receiving
1 is operated, the pressure on the rotor piston surface 14 becomes
Sufficiently until the measured value is once again within the predetermined reference range
To be increased.

In the case of the arrangement shown in FIG. 2, additional control conduits 15, 16 are provided, which are connected to the expansion turbine stage 4 at the rear side of the turbine rotor disk 3. And pressure regulators 17, 18 controlled by the regulator 9, respectively. Another rotor piston surface 19 at the rear of the expansion turbine stage rotor disk 3, which is hermetically sealed to the case 1 via these additional control conduits, is the turbine which prevails at the inlet of the expansion turbine stage 4. Supply pressure p ₃
And the turbine outlet pressure p _{4 at} the outlet of the expansion turbine stage 4. The additional rotor piston surface 19 is formed by the back surface of the turbine rotor disk 3 which is sealed to the case 1.
The configuration illustrated in FIG. 2 is considered when a very large compensating force is required to offset the axial thrust. At that time, the pressure regulating valves 10, 1 in the control conduits 12, 13
1 and the pressure control valve 1 in the additional control conduits 15 and 16
7 and 18 are switched in pairs so that the pressure difference between the rotor control surfaces 14 and 19 exerts an action aligned in the same direction. Thus, for example, a pressure increase at the rotor piston face 14 of the compressor rotor disc 5 is combined with a pressure decrease at the rotor control face 19 of the turbine rotor disc 3. Therefore, the pressure regulating valves 11 and 18
Is controlled.

In the case of the configuration shown in FIG.
So that the additional control conduits 15 and 16 each have one valve 2
It is equipped with 0 and 21. Valves 20 and 21 open quickly
Switching valve, for example, a magnetic valve. Impact style axial thrust variation
When the change occurs, one or the other, depending on the direction of the axial thrust.
Of the turbine rotor disk 3 by operating the switching valve of
The rotor piston surface 19 attached to the surface is
Force or high pressure p_Four, P _ThreeIs large enough to be operated
It Also, the measures described in FIGS.
It is understood that they can also be combined.

The rotor shaft 2 is supported in a high-precision angular contact ball bearing in each embodiment. This bearing is
It is possible to operate with rotational speed-diameter-product up to 2.5 × 10 ⁶ mm / min.

[0019]

According to the present invention, the turbo expander can be automatically adjusted, and the axial thrust compensation can be automatically performed in accordance with the operating conditions of various turbo expanders.

[Brief description of drawings]

FIG. 1 schematically shows a longitudinal section through a turbomachine with a device for axial thrust compensation formed according to the invention.

FIG. 2 schematically shows another form of the device according to the invention.

FIG. 3 schematically shows another form of the device according to the invention.

[Explanation of symbols]

1 case 2 rotor shaft 3 rotor disc 4 expansion turbine stage 5 rotor disc 6 compressor stage 7 measuring device 8 rolling bearing 9 regulator 10, 11 pressure regulating valve 12, 13 control conduit 14 rotor piston face p ₁ compressor inlet Pressure p ₂ Compressor outlet pressure F Force measurement value ΔF Reference value region 15, 16 Additional control conduit 17, 18 Pressure adjusting valve 19 Rotor piston surface p ₃ Turbine supply pressure p ₄ Turbine outlet pressure 20, 21 Valve

Claims (9)

[Claims] 1. A case (1), a rotor shaft (2), and an expansion turbine stage which is movably disposed at one shaft end of the rotor shaft (2) and which allows centripetal flow therethrough. 4) The rotor disk (3) and the rotor shaft (2) are movably arranged at the other end of the shaft.
A rotor disk (5) of a compressor stage (6) which is allowed to flow radially, and a measuring device (7) for directly detecting the axial thrust of a rotor shaft (2) supported in a rolling bearing (8). , And at least two pressure regulating valves controlled by a regulator (9) in the control conduit,
The rotor piston surface (14 or 19) on one rear side of the rotor disk (5 or 3), which is sealed to the case (1) via the control conduit, then prevails at the stage inlet and outlet. Pressures (p ₁ , p ₂ or p ₃ , p ₄ ) can be exerted, and the regulator (9) then applies the axial thrust located outside the predetermined tolerance range to the pressure at the rotor piston face. Either a pressure regulating valve in the control conduit acted on by a higher pressure or a pressure regulating valve on the control conduit present under a lower pressure, depending on the measured axial thrust, to eliminate by increasing or decreasing pressure A turbo machine that is configured to operate. 2. A rotor piston surface (14) at the back of the compressor rotor disk (5) is provided with a control conduit (11,1).
2) via a pressure prevailing at the inlet to the compressor stage (p ₁ ) and a pressure at the outlet of the compressor stage (6) (p ₂ ). In addition, the regulator (9) is actuated by the compressor inlet pressure (p ₁ ) depending on the measured axial thrust, either in the pressure regulating valve (10) in the control conduit (12) or at the compressor outlet pressure (p 1). _2. A turbomachine according to claim 1, characterized in that it is arranged to operate any one of the pressure regulating valves (11) in the control conduit (13) underneath ( ₂ ). 3. An expansion turbine stage
Rotor disk on the back of the rotor disk (3) of (4)
The stone surface (19) is connected via the control conduits (16, 15)
At the entrance to the expansion turbine stage
Pressure (p _Three) And the expansion turbine
Pressure at stage exit (p_Four) And can act
And the regulator (9) is
Depending on the measured axial thrust, the inlet pressure (p_Three) By
Pressure regulating valve (1) in the actuated control conduit (16)
7) or outlet pressure (p_FourControl conduit (1
Acts on one of the pressure control valves (18) in 5)
The structure according to claim 1, characterized in that
The turbo machine listed. 4. The additional control conduits are each provided with a valve, the additional rotor piston surface on the rear surface of the other rotor disc being sealed to the case via the additional control conduits. The turbomachine according to claim 1, wherein the turbomachine is configured so that the pressure prevailing at the entrance of the stage and the pressure at the exit of the stage can act. 5. A turbomachine according to claim 4, characterized in that the valve of the additional control conduit is arranged to be a pressure regulating valve (17, 18) controlled by a regulator (9). . 6. A turbomachine according to claim 4, characterized in that the valve of the additional control conduit is arranged to be a switching valve (20, 21) which opens rapidly. 7. The measuring device (7) comprises a ring-shaped force accommodating portion, and this force accommodating portion serves as an outer ring of a rolling bearing (8) on the case side which is loaded by the axial thrust of the rotor shaft (2). The turbomachine according to any one of claims 1 to 6, wherein the turbomachine is disposed between the case and the contact surface of the case (1). 8. The turbomachine according to claim 7, wherein the force accommodating portion includes a wire strain gauge. 9. Roller shaft (2) is mounted in a high-precision angular contact ball bearing, characterized in that
The turbo machine according to any one of 1.